The present invention generally relates to a catalytic converter for automobile use and, more particularly, to a catalytic converter having series-disposed two beds of catalyst material.
The U.S. Pat. No. 3,852,041, patented on Dec. 3, 1974, discloses a low profile catalytic converter which comprises substantially identical top and bottom housing plates and substantially identical top and bottom catalyst retaining plates sandwiched therebetween so as to define an inclined catalyst containing space of substantially uniform depth spaced inwardly at varying distances of the housing plates. The four plates have mating peripheral faces conterminous over substantially their entire peripheries adapted for edge-sealing and, further, define in combination peripherally spaced cylindrical contours adapted to receive exhaust inlet and outlet pipes. One of the contours is defined by a semicylindrical downwardly concave portion in the top housing plate, like-positioned downwardly concave portions in both retaining plates and an upwardly concave portion in the bottom housing plate while the other of the contours is similarly defined by the housing plates but with upwardly concave portions in both retaining plates. The use of a plurality of support studs is disclosed, which extend between the housing plates across the catalyst containing space to provide a converter having high structural integrity and increased resistance to deformation.
The U.S. Pat. No. 3,771,969, patented on Nov. 13, 1973, discloses a catalytic converter having a pair of catalyst containers arranged in longitudinally spaced relation to each other within a housing structure and between exhaust gas inlet and outlet. When taken in a direction parallel to the longitudinal axis of the housing structure, each of the catalyst containers employed in the second mentioned U.S. patent is of a generally rectangular cross section and, correspondingly, the housing structure for these catalyst containers is of a generally rectangular cross section when takan in a direction longitudinally thereof.
In particular, the catalytic converter of the construction disclosed in the second mentioned U.S. patent requires a relatively complicated fabricating procedure and, in particular, a boring technique is required to form a bearing hole through which a secondary air supply pipe is supported and projects into an intermediate chamber defined within the housing structure between the catalyst containers.